In the field of medical diagnostics and research including oncology, the detection, identification, quantification, and characterization of cells of interest, such as cancer cells, through testing of biological samples is an important aspect of diagnosis and research. Typically, a biological sample such as bone marrow, lymph nodes, peripheral blood, cerebrospinal fluid, urine, effusions, fine needle aspirates, peripheral blood scrapings or other biological materials are prepared by staining a sample to identify cells of interest.
In Fluorescent In Situ Hybridization (FISH) a fluorescently labeled oligonucleotide probe is added to a tissue sample on a microscope slide under conditions that allow for the probe to enter the cell and enter the nucleus. If the labeled sequence is complementary to a sequence in a cell on the slide a fluorescent spot will be seen in the nucleus when the cell is visualized on a fluorescent microscope. FISH has the advantage that the individual cells containing the DNA sequences being tested can be visualized in the context of the tissue.
FISH assays can be visualized with the naked eye as well as with video cameras. Problems are associated with both methods. Manual visualization by technicians results in the potential for subjective determinations and lack of reproducibility between one or more technicians viewing the same slide. Automated imaging with a camera takes several seconds for each area of a slide to be imaged to detect a fluorescent signal. In contrast, a camera on a bright field microscope can collect a new image every 1/60 of a second. Accordingly, a system that images all parts of a slide in about 6 minutes in bright field, may take an hour or more to collect a set of fluorescent images of the same slide. Thus a faster, more efficient, and reproducible method of imaging slides containing fluorescent agents is needed.